a) Field of the Invention
The invention is directed to a microtiter plate for screening processes using the method of reflectometric interference spectroscopy (RIS) for receiving a plurality of samples which are examined simultaneously or one after the other to detect physical, chemical, biological or biochemical reactions and interactions.
b) Description of the Related Art
A process and a device for carrying out testing of physical, chemical, biological or biochemical reactions and interactions using the method of reflectometric interference spectroscopy (RIS) are described in DE 196 15 366 A1. In this case, a plurality of samples which are arranged areally or in matrix form on a substrate plate are irradiated by light of different wavelengths from a tunable light source or scanning monochromator which is arranged following a polychromatic light source. Accordingly, the imaging of the radiation component reflected at a boundary surface of every sample is carried out by imaging elements arranged downstream on a spatially resolving detector array or a video camera. This enables wavelength-selective detection of the radiation intensities or intensities of the imaged interference which are influenced by the samples and also makes it possible to determine a wavelength-dependent interference spectrum associated with each of the samples and the derivation of parameters characterizing the reactions and interactions to be examined.
Microtiter plates, as they are called, are used for examination of the physical, chemical or biological characteristics of a quantity of samples in parallel. The samples to be examined are arranged in matrix form in small cavities or wells.
Microtiter plates of the type mentioned above are known, for example, from U.S. Pat. No. 5,457,527, WO 97/22754 and WO 95/03538. They comprise a specimen plate, or cavity plate, and a bottom plate, wherein the bottom plate is made of plastic or glass. The bottom plate and cavity plate are joined together in such a way that the bottom plate closes the wells of the cavity plate at the bottom. The bottom plate can be transparent. The bottom plate can be constructed in a special manner for special detection methods. For example, WO 95/22754 and WO 95/03538 describe microtiter plates which have a prism structure or lens structure or a grating structure at the location of each well. In both cases, the bottom plate is provided with coatings which are suitable for surface plasmon resonance (SPR) or form a waveguide channel for the light. These microtiter plates are accordingly configured for special applications of optical detection such as plasmon resonance methods or resonant mirror methods. Such elaborate microtiter plates with structures on the bottom plate are not required for use with RIS methods.
It is known from U.S. Pat. No. 5,319,436 and U.S. Pat. No. 5,457,527 to connect the bottom plate and the cavity plate through the action of heat, wherein the two plates are made of plastic, the bottom plate is transparent and the cavity plate is opaque.
As is known from DE 196 15 366 A1, the RIS process requires the arrangement of a determined transducer surface having a suitable RIS layer system. If this measurement process is to be carried out in a parallel manner, a matrix-shaped arrangement of the samples arranged in the wells is suitable for this purpose. A matrix arrangement corresponding to the standard grids of microtiter plates is recommended for favorable automatic handling of the liquid samples or samples dissolved in liquid.